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K2: Sudden CW filter FLT2~FLT4 shift!!

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Eddy

K2: Sudden CW filter FLT2~FLT4 shift!!

I thought it was just me...but chatting with another K2 owner whom experienced the same event, about a month ago I turned on me K2 and discovered all the CW filters Flt2 ~ Flt4 had shifted in relation to the BFO, all by the same amount!! My 680hz center was now off...

FLT1 and SSB had not shifted and was the same.

I figured this may have been due to "aging" of a component? Anyone experience this event? Any thoughts as to what may have occurred?

I realigned FLT2~FLT4 and they have been very stable since......

S/N: 3349 with all the latest mods including the Freq stability mod! Firmware 2.03d

Tnx much for your assistance!

73

Don Wilhelm-4

Re: K2: Sudden CW filter FLT2~FLT4 shift!!

There is nothing in the K2 that would shift only CW filters FL2 thru FL4
other than a re-adjustment of those filters themselves.

Is it possible that something happened to the BFO that has changed *all*
the filters, but the change was not enough to make a noticeable
difference when listening to the wider filters?

A BFO frequency shift would shift all the filters by approximately the
same amount - look for the unsoldered connection in the BFO area.

73,
Don W3FPR

k6sdw wrote:

> I thought it was just me...but chatting with another K2 owner whom
> experienced the same event, about a month ago I turned on me K2 and
> discovered all the CW filters Flt2 ~ Flt4 had shifted in relation to the
> BFO, all by the same amount!! My 680hz center was now off...
>
> FLT1 and SSB had not shifted and was the same.
>
> I figured this may have been due to "aging" of a component? Anyone
> experience this event? Any thoughts as to what may have occurred?
>
> I realigned FLT2~FLT4 and they have been very stable since......
>
> S/N: 3349 with all the latest mods including the Freq stability mod!
> Firmware 2.03d
>
> Tnx much for your assistance!
>
> 73
>

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dave.wilburn

Re: K2: Sudden CW filter FLT2~FLT4 shift!!

Just out of curiosity, if the ST P menu item was changed, to change
the CW tone, would that cause a similar shift? And by default that is
tied to the PF2 key, and would not be terribly hard to bring up by
mistake. I know I have done it.

Dave Wilburn
K4DGW
K2/100 - S/N 5982

Don Wilhelm wrote:

> There is nothing in the K2 that would shift only CW filters FL2 thru FL4
> other than a re-adjustment of those filters themselves.
>
> Is it possible that something happened to the BFO that has changed *all*
> the filters, but the change was not enough to make a noticeable
> difference when listening to the wider filters?
>
> A BFO frequency shift would shift all the filters by approximately the
> same amount - look for the unsoldered connection in the BFO area.
>
> 73,
> Don W3FPR
>
> k6sdw wrote:
>> I thought it was just me...but chatting with another K2 owner whom
>> experienced the same event, about a month ago I turned on me K2 and
>> discovered all the CW filters Flt2 ~ Flt4 had shifted in relation to the
>> BFO, all by the same amount!! My 680hz center was now off...
>>
>> FLT1 and SSB had not shifted and was the same.
>>
>> I figured this may have been due to "aging" of a component? Anyone
>> experience this event? Any thoughts as to what may have occurred?
>>
>> I realigned FLT2~FLT4 and they have been very stable since......
>>
>> S/N: 3349 with all the latest mods including the Freq stability mod!
>> Firmware 2.03d
>>
>> Tnx much for your assistance!
>>
>> 73
>>
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> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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> Elecraft web page: http://www.elecraft.com
>

Don Wilhelm-4

Re: K2: Sudden CW filter FLT2~FLT4 shift!!

Dave,

The ST P parameter changes only the sidetone pitch, it does not change
the filter centering.
BUT, the amount of transmit shift is determined by the ST P value, so
the transmit frequency will change, but the receive frequency stays the
same. That is why it is best to center your CW filters at the same
pitch as your sidetone.

73,
Don W3FPR

David Wilburn wrote:
> Just out of curiosity, if the ST P menu item was changed, to change
> the CW tone, would that cause a similar shift? And by default that is
> tied to the PF2 key, and would not be terribly hard to bring up by
> mistake. I know I have done it.
>
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